1. Field of the Invention
This invention relates to a consumable oxy-carbon arc electrode for exothermic cutting applications that is characterized by a higher combustion temperature, a longer life, and lower noise generation relative to conventional cutting rods.
2. Background Art
It is known in the art to use an exothermic cutting rod with a suitable torch for generating a high temperature flame by which to cut metal. The conventional exothermic cutting rod typically includes an elongated (about 18 inches) outer steel tube having an inner fuel material. In this case, the fuel material is generally a set of steel wires. Substantially pure oxygen is blown at high pressure through the interior of the outer steel tube. The torch has an associated low voltage source (e.g. a 12 volt battery) to ignite a catalytic spark at the end of the cutting rod. The primary disadvantage of an exothermic cutting rod is that the outer tube and inner fuel material thereof are consumed at a very high rate (in usually less than 60 seconds). Thus, a worker will be interrupted by having to make frequent replacements of fully consumed cutting rods.
It is also known in the art to use an air-carbon-arc cutting rod in a torch to cut metal. The air-carbon-arc cutting rod typically includes an elongated solid carbon rod. Compressed air is blown at high pressure along the exterior of the solid carbon rod. In this case, the torch has an associated high current source (e.g. from 250 to 600 amps) to ignite a cutting flame. The primary disadvantage of an air-carbon-arc cutting rod is that as a consequence of running high pressure compressed air along the exterior thereof, very high levels of noise (as much as 119 decibels) are generated. Subjecting a worker to such high noise levels while on the job can lead to increased stress and/or hearing problems over time.
Accordingly, it would be desirable to have a cutting electrode which would have a longer life prior to consumption, could be used in exothermic applications for cutting both ferrous and non-ferrous metals at substantially reduced noise levels, and would produce a cutting flame of relatively high temperature when compared with the conventional exothermic and air-carbon-arc cutting rods that have been described above.
Examples of conventional cutting torches and/or consumable electrodes for use therein are available by referring to the following U.S. patents:
In general terms, a consumable, oxy-carbon arc cutting electrode is disclosed that overcomes the problems inherent with the conventional exothermic and air-carbon-arc cutting rods. The oxy-carbon arc cutting electrode of this invention is adapted to be detachably connected to an oxygen exothermic torch that is coupled to a source of pure (e.g. 99%) oxygen gas under pressure. The cutting electrode includes a hollow, sacrificial cutting rod comprising an outer steel or carbon tube. A plurality of solid carbon fuel rods run through and are surrounded by the outer tube. The plurality of fuel rods are aligned with one another and positioned circumferentially around the interior of the outer tube. A central passageway extends longitudinally through the outer tube so as to lie in coaxial alignment with the circumferential arrangement of fuel rods. The central passageway establishes an air gap through which the pure oxygen gas is blown from the torch to which the cutting electrode is connected.
By blowing pure oxygen gas (rather than compressed air) down the central passageway of the cutting electrode and past the fuel rods thereof, the temperature of the cutting flame at the tip of the electrode can be increased. Moreover, any molten metal that accumulates within the central passageway during the cutting operation will be blown outwardly therefrom. The cutting operation can be completed under substantially reduced noise levels so as to alleviate worker discomfort. Finally, the life of the oxy-carbon arc cutting electrode of this invention will be substantially increased so as to avoid frequent and costly replacements.